Mounting means

ABSTRACT

The invention relates to a construction of vehicle rearview mirror which conforms with the Federal Safety Regulations concerning interior mirrors, namely, that the mirror mounting shall break away or deflect or collapse when struck by a force of 90 lbs. The mounting comprises a ball head on the mirror arm which fits within a complementary socket of a resilient plastics material, such as &#39;&#39;&#39;&#39;Delrin&#39;&#39;&#39;&#39;, forming the base part of the mounting. The arm also carries a shoulder which abuts the top of the base part and forms therewith a fulcrum about which the arm rocks to force the ball head out of the socket when the mirror is struck.

United States Patent 1 3,703,270 Tomlin [4 1 Nov. 21, 1972 [54] MOUNTINGMEANS 1,246,937 10/1960 France ..248/475 A 1,196,266 12/1966 GreatBritain ..248/476 R b t D k T 11 t [72] Inventor Hiil nglafrid om1,024,220 3/1966 Great Britain ..24/20s.3 1,096,178 12/1967 GreatBritain ..248/475 [73] Assignee: Magnatex Limited, Hounslow, MiddlBSeX,England Primary Examiner-J. Franklin Foss O Attorney-Edwin [21] Appl.No.: 82,373 [57] ABSTRACT Related US. Application DataContinuation-impart of Ser. No. 729,210, May 15, 1968.

5/1956 Germany ..248l479 The invention relates to a construction ofvehicle rearview mirror which conforms with the Federal SafetyRegulations concerning interior mirrors, namely, that the mirrormounting shall break away or deflect or collapse when struck by a forceof 90 lbs. The mounting comprises a ball head on the mirror arm whichfits within a complementary socket of a resilient plastics material,such as Delrin, forming the base part of the mounting. The arm alsocarries a shoulder which abuts the top of the base part and formstherewith a fulcrum about which the arm rocks to force the ball head outof the socket when the mirror is struck.

7 Claims, 10 Drawing Figures PATENTED now 21 :912

SHEET 2 BF 2 MOUNTING MEANS This application is a continuation-in-partof my copending application Ser. No. 729,210 filed May 15, 1968.

The present invention relates to blow-releasable mounting means and moreparticularly to a safety rearview mirror assembly for vehicles includinga blowreleasable connection means between the mirror and the base partby means of which the mirror assembly is adapted to be secured to thevehicle and which, while under normal conditions firmly secures andsupports the mirrors on the vehicle body, can, when struck by anabnormal blow, allow the mirror to become detached from the base partwhereby, for example in the event of an accident and a person within thevehicle being thrown against the rear-view mirror, the latter will bedetached and the risk of injury to the person, by striking the mirror,will be reduced.

The invention consists in a safety rear-view mirror assembly forvehicles including a blow-releasable connection means between the mirrorand the base part by means of which the mirror assembly is adapted to besecured to the vehicle, said blow releasable connection means comprisingfirst and second separable parts, said first part being provided with anundercut head, the underside of the head being inwardly tapered orcurved, and having a shoulder extending outwardly adjacent thetermination of the inwardly tapered or curved underside of the head, andsaid second part comprising a member of resilient plastics materialhaving a socket cavity in which said undercut head of the first part isfitted, said socket cavity having a mouth of smaller size than saidhead, the plastics material at said mouth being expandable to allow saidhead to be withdrawn therethrough to separate the two parts, saidshoulder, when said head is fitted in said socket cavity, abutting orlying close to a part at the mouth .end of said second part andconstituting with said shoulder a fulcrum about which said first andsecond parts can rock to withdraw the head from the socket cavity whenthe mirror receives a blow exceeding a predetermined value.

In one embodiment of the invention as applied to a vehicle interiorrear-view mirror, the resilient plastics socket part constitutes a basepart from which the mirror supporting arm, provided with the undercuthead and shoulder at one end, is carried. The base part is adapted to besecured to the vehicle body. The mirror head is carried from the freeend of the supporting arm. Upon the mirror receiving an abnormal blow,the supporting arm rocks about the fulcrum defined by the shoulder onthe arm and an adjacent surface of the base part whereby the head isforced out of the socket cavity.

In another embodiment, the socket cavity may be formed in a part at theback of the mirror head and be mounted on the head at the end of asupporting arm or member secured to the vehicle body.

Preferably the head is constituted by a ball member and the socketcavity is of corresponding part-spherical shape in which the balltightly fits. The surface or parts of the surface of the plasticsmoulding around the mouth of the socket cavity may constitute the partagainst which the shoulder abuts and fulcrums. According to a feature ofthe invention an annular recess is provided in the moulding around themouth of the socket cavity in order to facilitate the expansion of themouth when the head is forced out of the socket cavity. The forcerequired to release the supporting arm is determined by the resilientproperties of the plastics material and the position of the recess, andmay be further controlled by the provision of radial webs or abutrnentsdisposed at spaced locations in the recess.

The mouth of the socket cavity is preferably disposed slightly below thelevel of the surface parts against which the shoulder abuts and theconstruction of the head and shoulder is preferably such that when theparts are assembled together the resilient material forming the mouth ofthe socket will urge the shoulder into firm abutting contact with thebearing parts to avoid rocking between the parts in normal use.

According to another feature of the invention, indexing means areprovided for locating the first and second parts, when assembled, in aunique or one of several predetermined relative positions. It will beappreciated that if the headed member is spherical, then the supportingarm can be turned to several positions around the axis of the socketcavity and relies on the friction between the ball head and the socketfor remaining in .position. Positive indexing can be achieved byproviding the two parts with inter-engaging projections or recesses orby providing the ball head with one or more flats or equivalent meanscooperating with a complementarily shaped socket cavity.

In a preferred form, the indexing means includes cooperating inclinedsurfaces on said first and second parts respectively, such that upon themirror receiving a blow in a direction tending to turn the part carryingthe mirror about the axis perpendicular to the mouth of the socketcavity, the cooperating inclined surfaces of said indexing means willride up one upon the other, the height of said cooperating inclinedsurfaces being such that turning movement between the first and secondparts can move them relatively axially to an extent sufficient towithdraw the head from the socket cavity.

Conveniently, the indexing means comprises a V- shaped projection onsaid first part which locates in a V-shaped notch or recess in saidsecond part.

In order that the invention may be more clearly understood, referencewill now be made to the accompanying drawings, in which:

FIG. 1 is a section through an elementary embodiment of a rear-viewmirror according to the invention.

FIG. 2 is a side elevation, partly in section, of another embodiment ofrear-view mirror shown fitted to a part of a vehicle body,

FIG. 3 is a view of the base part looking in the direction of the arrowA in FIG. 2,

FIG. 4 is an exploded perspective view of the base part and thecooperating end of the supporting arm, but showing a modification of thebearing surfaces of the base part,

FIG. 5 shows a section through a modified construction,

FIG. 6 is a section through a moulding die explaining the method ofmaking the embodiment of FIG. 5.

FIGS. 7 and 8 show a perspective view and section of another embodimentof base part.

FIGS. 9 and 10 show scrap sections of further embodiments.

FIG. 1 shows an elementary construction in which the principle ofconstruction and operation of the mirror assembly according to thisinvention will be clearly apparent. In this embodiment the rear-viewmirror 1 is carried from a supporting arm 2 having a ball head 3 at itsend and a flange 4 forming a shoulder adjacent the undercut formation ofthe head defined by the inwardly curved surface of the ball between theplane indicated by the line X-X and the flange 4, said inwardly curvedsurface constituting the underside of the head. The ball head locates ina socket cavity 5 formed in a base part 6 moulded of a resilientplastics material and provided with apertures 7 for fixing the base partto a vehicle body.

The shoulder formed by the flange 4 abuts against the surface of theplastics moulding surrounding the mouth of the socket cavity 5 and uponthe mirror being struck with a blow the ball head 3 is forced out of themouth of the cavity by reason of the supporting arm 2 rocking about afulcrum defined by a point on the periphery of the shoulder and theabutting surface of the moulding.

FIGS. 2 to 6 show a more practical embodiment of a vehicle interiorrear-view mirror in which the supporting arm 2 for the mirror 1 ismounted on the base part 6, secured to the header bar 8 of the vehiclebody, by a safety knock-out mounting according to the invention. Thebase part 6 is moulded of a resilient plastics material with a bodyportion 9 in which a part-spherical socket cavity 5 is formed, and lugs10 provided with apertures 7 through which pass screws (not shown) forfixing the base part to the header bar.

The mouth of the socket cavity 5 is separated from the peripheralbearing portion 11 of the base by an annular recess 12, the continuityof which is interrupted by radial webs 13, preferably equallytherearound. The recess 12 extends into the moulding for such a depththat it reaches or almost reaches the level of the maximum diameter ofthe socket cavity.

Within the socket cavity 5 is located a metal ball member 3 projectingfrom the planar face 14 at the end of the supporting arm 1, said face 14constituting a shoulder which abuts the bearing surface portion 11 ofthe base.

The surface of the moulding between the mouth and the recess 12preferably lies just below the level of the bearing surface portion 11.This enables the shoulder 14 to be urged firmly against the bearingsurface portion 11 to reduce vibration of the supporting arm. Thedistance between the shoulder 14 and the center of the ball head 3 ismade slightly less than the distance between the level of the bearingsurface portion 1 l and the center of the socket cavity 5 so that theresilient plastics material forming the mouth of the cavity urges theshoulder 4 into firm contact with the bearing surface portion 11.

Instead of making the bearing surface portion 1 l as a continuousannulus, it may be constituted by a plurality of raised surfaceelements. FIG. 4 shows such a modification in which the raised surfaceelements are constituted by ribs lla. They may alternatively beconstituted by, for example, three or more raised projections.

If desired the supporting arm 2 may carry a steady 15 adapted to bearagainst the windscreen 16 to reduce spaced mirror vibration. The steady15 is made of very resilient rubber and of such a construction that itcan easily collapse if the supporting arm 2 is displaced by a blow.Adjustment of the steady is effected by the screw 17.

A suitable resilient plastics material from which the base part can bemoulded is Delrin" (Registered Trade Mark) supplied by DuPont. Othersuitable materials are Kamatol supplied by Imperial Chemical IndustriesLtd., polypropylene 'or polythene. The grade of the material used shouldbe such as to provide the necessary resiliency to allow the mouth of thesocket member to expand when the ball head is to be forced out on beingstruck with a force as prescribed by Official Safety Regulations whilstfirmly holding the supporting arm under normal conditions of use. TheSafety Regulations prescribed in the United States of America-requirethat the mounting shall break away without leaving sharp edges, ordeflect, or collapse, when the mirror is subjected to a force of lbs ina forward or sideward direction in any plane 45 above or below thehorizontal. The mirror assembly described with references to FIGS. 2 and3 conforms with these requirements using Delrin" of grade WT6l0 withfour radial webs in the annular recess. The construction describedenables the break-away force to be adjusted by modifying the grade ofthe resilient plastics material, the position of the annular recess andthe number and position of the radial webs.

If it be desired that the supporting arm should not turn about the axisof the socket cavity perpendicular to the mouth thereof, indexing meansmay be provided for locating the arm in one or several predeterminedpositions relative to said axis. Such location is achieved with theembodiment described with reference to FIGS. 2 to 4 by providing .theface 14 with a projection 18 which locates in a notch or recess 19 inthe base part 6.

According to a feature of this invention, the indexing means comprises aV-shaped projection 18 which locates in a corresponding V-shaped recess19 in the surface 11 of the body portion 9 of the base part 6 providingtwo pairs of cooperating inclined surfaces. The inclined surfaces of theprojection 18 and the corresponding inclined surfaces of the recess 19preferably converge at an angle of about 90. Upon the mirror 1 receivinga blow tending to turn the arm 2 carrying the mirror about the axisperpendicular to the mouth of the socket cavity 5, one of the inclinedsurfaces of the projection l8 and the cooperating inclined surface ofthe recess 19, depending on the direction of the blow, will ride up oneanother. The height of the cooperating inclined surfaces of theprojection 18 and recess 19 is such that the extent of axial movementbetween the arm 2 and base 6, at least when the above-mentioned turningmovement is sufficient to bring the inclined surfaces out of engagement,is sufficient to withdraw the head 3 from the socket cavity 5. Therecess 19 communicates at one end with the annular recess 12 surroundingthe mouth of the socket cavity 5 and the corner at the apex of theprojection 18 adjacent the closed end of the recess 19 is chamfered toavoid it fouling the end of the recess during the above-mentionedmovement.

The mirror 1 may be supported from the end of the arm by a conventionaladjustable joint.

The two parts of the mounting may be assembled by snapping the ball headin to the socket cavity. Alternatively the socket member may be mouldedaround the ball head as an insert in the moulding die. The ball head maybe a separate component which is subsequently secured to the arm bymeans of a screw or in any other convenient manner. Such a constructionis shown in FIG. 5 in which the ball head 3 is moulded as an insert inthe base part 6 which may be shaped similar to that shown in FIGS. 2 to4. The ball head is secured to the supporting arm 2 by a screw 21. Topermit insertion of the screw, the base member is moulded with anopening 22 extending to the bottom of the socket cavity 5. This openingis formed by a core pin projecting intothe hole in the ball memberduring the moulding operation.

FIG. 6 diagrammatically illustrates one form of mould cavity formoulding the base part with the ball member as an insert. The lowermould part 23 is formed with the cavity 24 in which the base part ismoulded, a core pin 25 projecting upwardly from the bottom of the cavity24 and supporting the ball member 3 in position. The mould cavity isclosed by the upper mould part 26. Plastics material is injected intothe mould cavity through the channel 26.

The base part and arm may assume shapes other than those described, andthe portion of the base which contains the socket cavity, instead ofprojecting forwardly of the part of the base to be secured to thevehicle body, may extend rearwardly so that the mouth of the socket liessubstantially flush with the surface of the vehicle body to which thebase member is secured. One such construction is shown in FIGS. 7 and 8from which it will be seen that the socket cavity 5 is formed in a partwhich projects rearwardly of the fixing plate 27. A base partconstructed similar to that shown in FIGS. 7 and 8 may be secured withinthe header bar. Further, the base member may be incorporated with othercomponcnts such as a courtesy light" fitting.

In another construction according to the invention, the socket membermoulded of resilient plastics material may be surrounded by a skirt ofmetal or other rigid material against which the shoulder on thesupporting arm is adapted to bear and which serves as a fulcrum for theshoulder when the supporting arm is rocked upon receiving an abnormalblow.

FIG. 9 shows one embodiment of such a construction in which the socketmember 6 of resilient plastics material is located in a metal base 28provided with holes 29 for securing it to the vehicle. The base isformed with a skirt portion 30 which surrounds and projects slightlybeyond the end of the socket member 6. The socket member is formed witha flange 31 which fits in a recess in the underside of the base, thesocket member being secured in position by a plate 32 secured to thebase by screws 33. The supporting arm 2 having the ball head 3 andshoulder 4 is releasably secured in the socket cavity, the arrangementbeing such that in this position the shoulder 4 bears against the end ofthe skirt 30. A slight clearance is provided between the skirt 30 andthe socket member 6 to allow the mouth of the latter to expand slightlywhen the ball head is which, when the socket member is inserted in thebase, engages in an annular recess 35 around the internal wall of theskirt 30 to retain the socket member therein.

The blow-releasable mounting according to this invention has theadvantage that the two parts can easily be snapped together again afteran accident in which the mirror has become detached, thus enabling thecar, if not seriously damaged, to-be driven with the rearview mirrorfitted back in place.

While particular embodiments have been described, it will be understoodthat various modification may be made without departing from the scopeof the invention. For example the underside of the head can have otherthan a part-spherical shape, such as frustro conical or pyramidal. Thehead may also be shaped like a section of a cylinder.

The indexing means may comprise two of the V- shaped projections 18provided on the face 14 at diametrically opposite sides of the head 3which locate in two corresponding V-shaped recesses in the surface 11.The projections may be shallow V-Shaped projections extending across thewidth of the shoulder which fit in complementary shallow V-shapedrecesses extending across the width of the surface 11. Further, the face14 may have a shallow V-shaped profile and bear in a complementaryshallow V-shaped recess constituting the surface 11. If several indexingpositions are required, the opposing surfaces of the shoulder and thebearing surface or skirt may be formed with radial teeth.

Other means of indexing the position of the arm around the axis of thesocket cavity may also be used. For example, the ball head may beprovided with one or more flats or splines cooperating with acomplementarily shaped socket. If the head has an undercut of pyramidalor other non-circular section, indexing is achieved by the configurationof the head.

lclaim:

l. A safety rear-view mirror assembly for vehicles, including ablow-releasable connection means between the mirror and the base part bymeans of which the mirror assembly is adapted to be secured to thevehicle, said blow-releasable connection means comprising first andsecond separable parts, said first part being provided with an undercuthead, the underside of the head being inwardly sloping and having ashoulder extending outwardly adjacent the termination of the inwardlysloping underside of the head, and said second part comprising a memberof resilient plastics material having a socket cavity in which saidundercut head of the first part is fitted, said socket cavity having amouth of smaller size than said head, the plastics material at saidmouth being expandable to allow said head to be forced therethrough toseparate the two parts, said shoulder, when said head is fitted in saidsocket cavity, abutting parts of the surface of the moulding around themouth of the socket cavity which constitute with said shoulder a fulcrumabout which said first and second parts can rock to withdraw the headfrom the socket cavity when the mirror receives a blow exceeding apredetermined value, and said moulding being formed around the mouth ofthe socket cavity with an annular recess, and the mouth of the socketmember being disposed slightly below the level of the parts againstwhich the shoulder abuts such that the plastics material forming themouth of the socket urges the head in a direction to hold the shoulderin firm abutting contact with said parts.

2. A safety rear-view mirror assembly for vehicles as claimed in claim1, in which the undercut head is a ball and the first part comprises asupporting arm having said ball at one end and a mirror adjustablymounted at the other end, and said annular recess is interrupted byradial webs disposed at spaced locations therearound.

3. A safety rear-view mirror assembly for vehicles including ablow-releasable connection means between the mirror and the base part bymeans of which the mirror assembly is adapted to be secured to thevehicle, said blow-releasable connection means comprising first andsecond separable parts, said first part being provided with an undercuthead, the underside of the head being inwardly sloping and having ashoulder extending outwardly adjacent the termination of the inwardlysloping underside of the head, and said second part comprising a memberof resilient plastics material having a socket cavity in which saidundercut head of the first part is fitted, said socket cavity having amouth of smaller size than said head, the plastics material at saidmouth being expandable to allow said head to be. forced therethrough toseparate the two parts, said shoulder, when said head is fitted in saidsocket cavity, being adjacent to parts at the mouth end of said secondpart and constituting with said shoulder a fulcrum about which saidfirst and second parts can rock to withdraw the head from the socketcavity when the mirror receives a blow exceeding a predetermined value,and indexing means comprising cooperating cooperating means on saidshoulder and the surface of the plastics material adjacent the mouth ofthe socket cavity, said cooperating means being a projection and arecess for locating said first and second parts in a predeterminedposition about the axis perpendicular to the mouth of the cavity.

4. A mirror assembly as claimed in claim 3, wherein the plastics socketmember is provided around the mouth of the socket cavity with an annularrecess.

5. A. mirror assembly as claimed in claim 4, wherein said recess isinterrupted by radial webs disposed at spaced locations therearound.

6. A mirror assembly as claimed in claim 3, wherein said indexing meansincludes cooperating inclined surfaces on said projection and recessrespectively, such that upon the mirror receiving a blow in a directiontending to turn the part carrying the mirror about the axisperpendicular to the mouth of the socket cavity, the cooperatinginclined surfaces of said indexing means will ride up one upon theother, the height of said cooperating inclined surfaces being such thatturning movement between the first and second parts can move themrelatively axially to an extent sufficient to withdraw the head from thesocket cavity.

7. A mirror assembly as claimed in claim 6, wherein said projection is aV-shaped projection and said recess is a V-shaped recess receiving saidprojection.

1. A safety rear-view mirror assembly for vehicles, including ablow-releasable connection means between the mirror and the base part bymeans of which the mirror assembly is adapted to be secured to thevehicle, said blow-releasable connection means comprising first andsecond separable parts, said first part being provided with an undercuthead, the underside of the head being inwardly sloping and having ashoulder extending outwardly adjacent the termination of the inwardlysloping underside of the head, and said second part comprising a memberof resilient plastics material having a socket cavity in which saidundercut head of the first part is fitted, said socket cavity having amouth of smaller size than said head, the plastics material at saidmouth being expandable to allow said head to be forced therethrough toseparate the two parts, said shoulder, when said head is fitted in saidsocket cavity, abutting parts of the surface of the moulding around themouth of the socket cavity which constitute with said shoulder a fulcrumabout which said first and second parts can rock to withdraw the headfrom the socket cavity when the mirror receives a blow exceeding apredetermined value, and said moulding being formed around the mouth ofthe socket cavity with an annular recess, and the mouth of the socketmember being disposed slightly below the level of the parts againstwhich the shoulder abuts such that the plastics material forming themouth of the socket urges the head in a direction to hold the shoulderin firm abutting contact with said parts.
 1. A safety rear-view mirrorassembly for vehicles, including a blow-releasable connection meansbetween the mirror and the base part by means of which the mirrorassembly is adapted to be secured to the vehicle, said blow-releasableconnection means comprising first and second separable parts, said firstpart being provided with an undercut head, the underside of the headbeing inwardly sloping and having a shoulder extending outwardlyadjacent the termination of the inwardly sloping underside of the head,and said second part comprising a member of resilient plastics materialhaving a socket cavity in which said undercut head of the first part isfitted, said socket cavity having a mouth of smaller size than saidhead, the plastics material at said mouth being expandable to allow saidhead to be forced therethrough to separate the two parts, said shoulder,when said head is fitted in said socket cavity, abutting parts of thesurface of the moulding around the mouth of the socket cavity whichconstitute with said shoulder a fulcrum about which said first andsecond parts can rock to withdraw the head from the socket cavity whenthe mirror receives a blow exceeding a predetermined value, and saidmoulding being formed around the mouth of the socket cavity with anannular recess, and the mouth of the socket member being disposedslightly below the level of the parts against which the shoulder abutssuch that the plastics material forming the mouth of the socket urgesthe head in a direction to hold the shoulder in firm abutting contactwith said parts.
 2. A safety rear-view mirror assembly for vehicles asclaimed in claim 1, in which the undercut head is a ball and the firstpart comprises a supporting arm having said ball at one end and a mirroradjustably mounted at the other end, and said annular recess isinterrupted by radial webs disposed at spaced locations therearound. 3.A safety rear-view mirror assembly for vehicles including ablow-releasable connection means between the mirror and the base part bymeans of which the mirror assembly is adapted to be secured to thevehicle, said blow-releasable connection means comprising first andsecond separable parts, said first part being provided with an undercuthead, the underside of the head being inwardly sloping and having ashoulder extending outwardly adjacent the termination of the inwardlysloping underside of the head, and said second part comprising a memberof resilient plastics material having a socket cavity in which saidundercut head of the first part is fitted, said socket cavity having amouth of smaller size than said head, the plastics material at saidmouth being expandable to allow said head to be forced therethrough toseparate the two parts, said shoulder, when said head is fitted in saidsocket cavity, being adjacent to parts at the mouth end of said secondpart and constituting with said shoulder a fulcrum about which saidfirst and second parts can rock to withdraw the head from the socketcavity when the mirror receives a blow exceeding a predetermined value,and indexing means comprising cooperating cooperating means on saidshoulder and the surface of the plastics material adjacent the mouth ofthe socket cavity, said cooperating means being a projection and arecess for locating said first and second parts in a predeterminedposition about the axis perpendicular to the mouth of the cavity.
 4. Amirror assembly as claimed in claim 3, wherein the plastics socketmember is provided around the mouth of the socket cavity with an annularrecess.
 5. A mirror assembly as claimed in claim 4, wherein said recessis interrupted by radial webs disposed at spaced locations therearound.6. A mirror assembly as claimed in claim 3, wherein said indexing meansincludes cooperating inclined surfaces on said projection and recessrespectively, such that upon the mirror receiving a blow in a directiontending to turn the part carrying the mirror about the axisperpendicular to the mouth of the socket cavity, the cooperatinginclined surfaces of said indexing means will ride up one upon theother, the height of said cooperating inclined surfaces being such thatturning movement between the fIrst and second parts can move themrelatively axially to an extent sufficient to withdraw the head from thesocket cavity.